At this size your best foods are those that are soft and float. Freeze dried blood worms work well, also do freeze dried baby krill/shrimp just make sure they are soft(some brands are too hard).
Your new aros will eat when they are adjusted which could take a few days.
Thanks for the input guys...I am going to try freeze dried blood work....they have been eating blood worms from my hand but the worms are to small and if they miss it.. .sinks to the bottom...to rot